Earning your stripes refers to putting in hard work and effort and earning respect from your peers as a result. Similar to mitary rank and displaying military stripes, moving up the chain of command from sergeant to Lieutenant to captain to major
Taeshawn: Did you see Omar putting in mad work after school in the gym?
Julius: Yep, he's earning stripes with the coach, Omar might be playing varsity ball this year.
Victor: Damn ese, Julio's been pushing mad weight lately homie, he pushed a key last week.
Jorge: Yea ese, the vatos in the barrio are saying that he's earning stripes with the O.G.'s.